Hancock Industrial Ltd can supply a range of optimized structure-borne noise decoupling systems for architectural acoustics. We carry a selection of AMC AKUSTIK and AKUSTIK + SYLOMER products. Acoustic suspended ceilings are an excellent way of preventing airborne noise from below passing into the ceiling structure, or preventing noise/vibration from the floor above entering the room below. In addition AMC produce a range of floor and wall mounts to provide structure borne noise transmission in residential and commercial buildings. Go to https://www.mecanocaucho.com/en-GB/products/acoustic-hanger-mounts/#videos for sample videos of Akustik + Sylomer installation techniques.
For more information and samples please contact our technical team at Hancock Industrial Ltd.
Subsequent to the Christchurch earthquakes, generators for infrastructure services are now frequently being specified to incorporate seismic mounts.
The Christchurch wastewater treatment plant now has a MTU 650 kVA standby generator supplied by Powergen. The generator is enclosed in a weatherproof and sound attenuating container, and is mounted on AMC seismic vibration isolators to minimise structure borne noise and vibration, and to provide safety and stability in the event of further seismic disturbances. At normal operating speeds, the mounts will provide over 95% vibration isolation.
After trouble-free service of 13 years, the New Zealand Navy has asked Trelleborg Industrial AVS to supply a new set of Metalastik® engine mounts for its Anzac Class frigates, to replace the mounts the company originally delivered to Tenix Defence Systems (now BAE) in 1993.
The bearings have been supplied through Hancock Industrial Ltd, Trelleborg’s New Zealand representative for this project. A total of ten ANZAC frigates were built at Tenix Defence Systems in Australia, of which the two belonging to the New Zealand Navy are now undergoing a mid-life refurbishment. When built, the Te Kaha and the Te Mana were each powered by one General Electric LM2500+ gas turbine and two MTU 12V1163 TB83 diesels driving two variable pitch propellers.
Now, the diesels are being replaced with two MTU 12V1163 TB93 engines, with a combined output of 8800 kW at 1350 rpm and weighing 16,000 kg each. The new engines, which will have their own sets of Metalastik® mounts, are each supplied by MTU on a raft. These rafts in turn will be supported on a total of 32 large Metalastik® Super-D mounts together with eight elastomeric buffers to restrain horizontal movement. The mounts are supplied by Trelleborg Industrial AVS pre-compressed to allow easy installation, so saving considerable amounts of working time at the shipyard.
Metalastik® Super-D mounts are rubber/metal bonded assemblies specially developed for arduous marine applications. They are capable of nominal static deflection of 23mm and up to 50mm shock excursions in any direction.
Trelleborg Industrial AVS is to supply anti-vibration and suspension components for a new backhoe loader developed by the Mahindra Group of Mumbai, India. Mahindra has chosen Trelleborg’s Metacone and EH mounts to isolate the engine and cab in its new backhoe loader, due for launch 2011. This indicates a commitment to ensuring world-class levels of noise and vibration suppression.
The TrellExtreme® Metacone mount is a robust rubber/metal unit combining bump and rebound control with good vibration isolation. It is designed to provide high load capacity together with relatively significant deflections in the axial direction and is available in a range of sizes for loads from 30kg to1000kg. It has an exceptionally long and successful track record, due in part to its ability to deliver operator comfort, while also helping to protect the engine, running gear and vehicle body from the effects of shock and vibration.
TrellExtreme® EH mountings are designed primarily for mobile applications such as construction equipment, agricultural, materials-handling and off-highway vehicles, to compensate for high dynamic and shock forces. The mountings consist of an assembly of two rubber/metal elements which provide excellent horizontal stability while restricting dynamic vertical movements in both directions. Simple, fail-safe and easy to install, the design attenuates structure-borne noise, accommodates any misalignment or distortion and is available for loads from 60kg to 350kg.
The Mahindra Group is a diverse USD 6.7 billion corporation, active in the automotive, farm equipment, financial services, trade and logistics, automotive components, after-market, IT and infrastructure sectors. The company has grown from being a maker of army vehicles to a major automobile and tractor manufacturer with plants in China, the UK and the USA. It is the third largest tractor company in the world and already manufactures a range of backhoe attachments for tractors.
ATP/Trelleborg track fasteners for the Kowloon Southern Loop
Advanced Track Products and Trelleborg Industrial AVS have won a second major Chinese contract to supply CBP (compression base plate) track fasteners, in this case for the new Kowloon Southern Loop (KSL), which extends Hong Kong’s West Rail heavy rail line from Nam Cheong to Hung Hom.
The CBP fastener is a rugged, low-maintenance design providing moderate track stiffness in ballast-less track, together with long service life in nominal 20 ton axle applications. It improves ride quality and reduces ground and structure-borne vibration, which can cause secondary effects of noise and even structural damage in neighbouring buildings and transit tracks. The design consists of two metal components – the top plate and frame, bonded together with an elastomer, normally rubber, specially compounded to optimise overall performance.
The fasteners are installed with the rail resting on the top plate and are secured by two or four anchor bolts, which do not pierce the plane of the top plate and so the anchor bolts are isolated from the rail forces. The elastomer ensures that the rail is completely separated from its containment frame (which physically limits uplift) and provides excellent electrical insulation as well as cushioning the track.
The current phase of Hong Kong’s railway projects is designed to serve the new growth areas and meet increasing transport demand due to improved links with the mainland. KSL is one of several projects that will expand the present network by 70 per cent to 250km of track, costing some HK$80 billion at today’s prices and bringing more than 80 per cent of the total population within reach of rail services. Floating slab track is used both at stations and in tunnels to prevent vibrations being transmitted to any existing or future developments, including the 40,000 apartments that the government plans to build alongside the stations.
Trelleborg Industrial AVS is supplying Metalastik® Cushyfloat™ engine mounts to Volkswagen Marine for its new high output, lightweight TDI 225-6 six-cylinder turbo diesel.
The TDI 225-6 weighs only 325 kg. and is more than 100 kg. lighter than other marine diesels of comparable output.Based on the latest V-6 used in Audi A6, Audi A8 and VW Touareg cars, the compact three-litre engine employs a piezo-controlled, third-generation common rail injection system.Output is 225 hp at 4,200 rpm or 450 newton/metres of torque at 2,000, a profile ideally suited to accelerate the heavier powerboats on to the plane.It is initially offered in sterndrive configuration with Mercruiser Bravo 1 or Bravo 3 drives and also ZF gearboxes.
To meet the demands of this level of engine performance, Trelleborg Industrial AVS is supplying Cushyfloat™ mounts which are fitted either in a four point mounting system or two point when coupled to a Z-Drive gearbox.The Metalastik® Cushyfloat™ is a compact, low-profile mounting, combining three-way control of engine movement with relatively large deflection in the rubber element.A correctly mounted bearing provides maximum flexibility at right angles to the crankshaft, while the direction of maximum stiffness is in the fore and aft horizontal plane, the optimum arrangement for vibration damping and to accommodate propeller thrust.
Metalastik® Cushyfloat™ mounts are available in a range of sizes and three different rubber formulations to carry loads from 32 kg to 800 kg per unit and with natural frequencies down to 8 Hz.The metal parts are zinc-plated and the mounts incorporate bump and rebound control features to limit excessive movements under shock loads.All parts are designed to meet the highest standards of reliability, acoustic efficiency and shock protection in accordance with BS EN ISO 9001, Lloyds Register of Shipping, Det Norske Veritas and other authorities.
Trelleborg Industrial AVS (TIAVS) has won a major contract to supply Metalastik® Chevron™ springs for new light rail vehicles being built by Rotem of South Korea for Istanbul’s light rail system.
Trelleborg is supplying over 800 Metalastik® chevrons™ as primary suspension springs. They are fitted in pairs between the wheel axles and bogie frame to give longitudinal, vertical and lateral flexibility and are designed to absorb high levels of shock and vibration. Metalastik® chevrons™ are built to a special non-linear design, ensuring progressive spring stiffness and providing greater flexibility at full load.
The design was pioneered on London Underground over 50 years ago. Since then many thousands have given reliable, low-maintenance service in locomotives, high-speed passenger coaches, freight wagons and metros throughout the world. Trelleborg Industrial AVS offers over 50 different types of chevron springs for axlebox loadings ranging from 16kN to 120KN and vertical deflections from 12mm to 100mm.
Rotem’s light rail vehicles are destined for Istanbul and will be operated by IETT (Istanbul Elektrik Tramvay in Tünel Íşletmeleri) on the route connecting the Otogar bus station with the Bagcilar suburb. They will travel in three-car sets at a maximum speed of 80 kph and will be powered by 750 V DC motors. There are more than 8 million people travelling in Istanbul every day and of these only 8% are carried by rail, a figure which is expected to rise to 43% when all current projects are complete.
Rotem is part of the Hyundai Motor Group and, in addition to light rail vehicles, its Changwan-based rail division designs and manufactures electric and diesel locomotives, Maglev and high-speed trains, suburban train units, passenger and freight wagons.
Caterpillar Elphinstone is fitting heavy-duty cab mounts from Trelleborg Industrial AVS throughout its range of LHD (long haul dump) underground mining loaders.
The machines fitted with Trelleborg cab mounts are the R1300G, R1600G, R1700G and the R2900G LHDs, designed and built by Caterpillar Underground Mining in Burnie, Tasmania, Australia.Powered by Caterpillar engines from 136 kW to 321 kW gross power, they weigh from 27 tonnes to 67 tonnes.These vehicles are capable of carrying payloads from 6,800 kg to 20,000 kgup slopes of 1 in 5 or 20%.
All machines in the range offer a choice between an open operator station and an enclosed cab.The open option incorporates a protective structure in accordance with ROPS (roll-over) and FOPS (falling object) regulations and is resiliently mounted via Treleborg’s TrellExtreme ® Ultra Duty bushes.UD bushes are also used to isolate the optional enclosed cab, which offers a sound-suppressed working environment, as well as fresh, pressurized temperature-controlled air circulation, ergonomic design and a high level of comfort.
TrellExtreme® UD bushes are extremely rugged rubber/metal assemblies designed to permit oscillating movement through deflection in shear and compression.They do not require lubrication and so are virtually maintenance-free.In this application, their primary function is to protect the cab from noise and vibration and to ensure a comfortable, resilient ride for the operator as the vehicle travels over rough and difficult terrain underground.However, working in such demanding conditions, the machines and their Trelleborg cab mounts also have to withstand occasional high-impact loads when the operator accidentally grazes the walls of the underground driveways.
“Earthrace” trimaran breaks round-the-world record with Trelleborg Industrial AVS engine mounts
“Earthrace”, New Zealand’s 78ft wave-piercing trimaran, has broken the worldrecord for circumnavigating the globe, covering a distance of 24,000 nautical miles in a time of 60 days, 23 hours and 49 minutes, and beating the previous record by around 14 days.
Running exclusively on 100% biodiesel, “Earthrace” has a net zero carbon footprint and the record attempt was designed to demonstrate the efficiency of, and draw attention to the potential for, alternative fuel sources.It is powered by two Cummins MerCruiser Diesel QSC8.3-540 diesels, each mounted on four Metalastik® Cushyfloat® HT™ high-performance elastomeric engine mounts.Trelleborg Industrial AVS designed and donated a new engine mounting system to cope with the massive forces encountered during the voyage.
Starting from Valencia, Spain, “Earthrace” travelled via the Azores, Puerto Rico, Panama Canal, Manzanillo, San Diego, Hawaii, Marshall Islands, Palau, Singapore, Kochi, Salalah and the Suez Canal, crossing the finishing line in Sagunto on 27 June at 13.24 GMT.The previous world speed record of 75 days was set by Cable and Wireless Adventurer (GB) in 1998.
Trelleborg Industrial AVS was asked to design a new mounting system because the the one originally provided by another manufacturer proved inadequate during the course of last year’s initial record attempt, which had to be abandoned due to extreme weather in the Mediterranean.The solution proposed by Trelleborg Industrial AVS was a conventional four-point mounting system based on the new Metalastik® HT™ (High Thrust) Cushyfloat®, which has been specifically designed for higher thrust loading and higher torque output of modern marine engines.
The rubber element of the Metalastik® HT™ Cushyfloat® is precisely configured to combine a relatively high degree of flexibility in the vertical and lateral modes, together with good longitudinal stiffness fore and aft.This means excellent vibration isolation properties with minimum movement under thrust forces.
Metalastik® HT™ Cushyfloat® incorporates bump and rebound control features to limit excessive movement under shock and a corrosion-resistant metal cover to protect the rubber against oil contamination.Trelleborg Industrial AVS offers the Metalastik® HT™ Cushyfloat® in two basic designs and a variety of rubber compounds to accommodate loads from 85 to 900 kg.
“Earthrace” is a not-for-profit project led by skipper Pete Bethune (NZ) and with volunteers providing the crew and back-up.The boat itself was designed and built in New Zealand by Calibre Boats, using carbon/kevlar composites.It has a maximum speed of 40 knots, can carry 3,000 gallons (11,500 litres) of fuel and has a range of 14,000 nm at 6 knots.It is designed to take up to 24ft (7metres) of water on top of the windscreen and the wave piercing is controlledby pumping up to 2.5 tons of water into a special ballast tank in the bow.The more water in the bow and the faster the boat is travelling, the more effectively it pierces the waves.
Trelleborg IAVS suspension components help lower noise produced by wind turbines.
Trelleborg Industrial AVS has been supplying anti-vibration bearings to the wind energy sector ever since the 1990’s. One of the first applications was at Cemmaes in Powys, mid Wales in 1992, where Wind Energy Group Ltd. (WEG) built 24 turbines for National Wind Power, making it the largest UK wind farm to use British machinery at that time. The WEG MS-3 turbines were equipped with 33m diameter wood epoxy composite blades rotating at 48rpm on a 25m steel tower and generating up to 400KW.
Some of the earlier wind turbines attracted considerable criticism on the grounds of noise, so WEG paid particular attention to acoustic isolation in the design of the MS-3. The main noise attenuation feature was a Metalastik ® Spherilastik “teeter”bearing from Trelleborg Industrial AVS, which allowed the rotor blade to tilt on its hub, counteracting the see-sawing motion caused by gusting wind. In addition to acting as a resilient spherical joint, the compact, precisely formulated rubber/metal component also keeps noise and vibration to a minimum. Spherilastik bearings are designed for un-lubricated, maintenance-free operation and are typically used in rail, road and off-road vehicles, hydraulic damper fixings and other applications where a high duty bearing of compact size is required.
Two years later Trelleborg Industrial AVS developed a more complex isolation system for the wind farm at Blyth in Northumberland, the first in the UK to be sited in a harbour. In this case, the computer-controlled 300kW turbines were supplied by the Belgian company Windmaster. The Trelleborg suspension system was installed in the three turbines closest to the town two years after it opened in order to bring overall noise levels within the environmentally acceptable norms specified by the contract.The package consisted of four Spherilastik and a number of large Metalastik® Cushyfloats for each of the three turbines.Measurements showed that this mounting system achieved a reduction of 4 dBA in structure-borne noise.
Since these early installations, the company’s anti-vibration technology has won wide international acceptance in the wind energy industry.From the mid-1990s the volume of export contracts has grown steadily.An early example, was the technology exchange between WEG and the Kirloskar Electric Company of Bangalore, India, which saw the introduction of the first TIAVS rubber/metal bearings into wind farms on the sub-continent.The most recent example is Trelleborg’s collaboration with Windflow Technology of Christchurch, N Z, which again is using Spherilastik bearings for its Windflow 500 wind turbines, designed and manufactured in New Zealand.
The Windflow 500 design is almost unique in the world of wind power, featuring, as it does, two blades rather than the more conventional three-bladed solution.In addition to being inherently lighter and more economic to manufacture and install, two blades enable the unit to teeter, which is important as it reduces the bending forces on the turbine shaft, gearbox, tower and foundations.As a result, all of these elements can be lighter and less expensive too.The rotor of the Windflow 500 turbine is designed to teeter up to 6 degrees on either side of the normal plane of rotation in response to varying wind forces.In addition, the Windflow 500 is a medium-sized design, measuring 47m from the tower baseto the blade tip, less than a third the height of some of the larger three-bladed turbines.This dramatically reduces the environmental impact, making it much more acceptable to planners and to neighbouring communities.
As usual, the Trelleborg bearings form part of the pitch-teeter coupling mechanism in the hub of the Windflow turbine.The two-bladed rotor is mounted on a hinge, allowing it to teeter back and forth slightly as it rotates.The mechanical pitch coupling permits passive pitch movement and changes the natural frequency of teetering, away from resonance, so minimizing teeter restraint loads.
Along with this pitch teeter coupling feature, Windflow utilizes a patented, torque-limiting gearbox incorporating a narrow band variable speed system.This, together with full blade pitch control, allows the use of a synchronous generator, coupled directly on line – a first for the wind industry.The Windflow 500 can therefore be connected easily into the electrical grid, as grid compliance codes have been designed around the capability of this generator.
The application of these two weight-saving technologies makes the turbine more cost-effective than comparable three-bladed designs.The rotor and gearbox are also very robust so they can generate more energy in windy conditions and are designed to last for at least 20 years.
Trelleborg’s Spherilastik bearings act as a resilient spherical joint, providing articulation and allowing the rotor hinge mechanism to pivot, while also suppressing noise and vibration.
The first five production turbines have been performing extremely well at the Te Rere Hau wind farm near Palmerston North – an area that experiences some of the strongest winds in the world.Windflow Technology is currently building a further batch of fourteen turbines for this 97-turbine wind farm and plans to build over 60 turbines per year from 2008, predominantly for the New Zealand market and Pacific Rim countries such as Australia and USA.